In active use of edge-emitting lasers, in recent years, interest in the vertical cavity surface emitting laser (VCSEL) has been increasing. The VCSEL is a semiconductor laser that emits a laser in a vertical direction on an upper surface and has advantages in that it is easy to mass produce because of its simple manufacturing process and it is able to be manufactured in a small size because of its high degree of integration.
The VCSEL has mostly been applied to the telecommunications field, but recently, attempts to apply the VCSEL to the optical system have been vigorously made. Particularly, with autonomous-driving vehicles being in the spotlight, attempts to apply the VCSEL to a light detection and ranging (LiDAR) device have been vigorously made.